Gamma Pyxidis

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Gamma Pyxidis
Diagram showing star positions and boundaries of the Pyxis constellation and its surroundings
Cercle rouge 100%.svg

Location of γ Pyxidis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Pyxis
Right ascension 08h 50m 31.9233s[1]
Declination −27° 42′ 35.440″[1]
Apparent magnitude (V) 4.026[2]
Spectral type K3III[2]
U−B color index +1.368[3]
B−V color index +1.284[3]
Radial velocity (Rv) 24.5 km/s
Proper motion (μ) RA: −133.49[1] mas/yr
Dec.: 88.16[1] mas/yr
Parallax (π) 15.63 ± 0.58[1] mas
Distance 209 ± 8 ly
(64 ± 2 pc)
Luminosity 178[4] L
Surface gravity (log g) 2.35[5] cgs
Temperature 4,270[5] K
Metallicity [Fe/H] -0.05[5] dex
Other designations
γ Pyxidis, γ Pyx, Gamma Pyx, CPD−27  3442, FK5 332, GC 12216, HD 75691, HR 3518, PPM 255235, SAO 176559.

Gamma Pyxidis (Gamma Pyx, γ Pyxidis, γ Pyx) is a 4th magnitude star in the constellation Pyxis. It is classified as a giant star of composition similar to the Sun[6] and is located an estimated 209 light years[1] from the Solar System.

Gamma Pyxidis is moving through the Galaxy at a speed of 54.2 km/s relative to the Sun. Its projected Galactic orbit carries it between 21,300 and 30,700 light years from the center of the Galaxy.[7]


In Chinese, 天狗 (Tiān Gǒu), meaning Celestial Dog, refers to an asterism consisting of γ Pyxidis, e Velorum, f Velorum, β Pyxidis, α Pyxidis and δ Pyxidis. Consequently, γ Pyxidis itself is known as 天狗六 (Tiān Gǒu liù, English: the Sixth Star of Celestial Dog.)[8]


  1. ^ a b c d e f Perryman, M. A. C. et al. (1997), "The Hipparcos Catalogue", Astronomy & Astrophysics 323: L49–L52, Bibcode:1997A&A...323L..49P 
  2. ^ a b "gam Pyx", SIMBAD (Centre de Données astronomiques de Strasbourg), retrieved 2009-06-03 
  3. ^ a b Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168 
  4. ^ Mallik, Sushma V. (December 1999), "Lithium abundance and mass", Astronomy and Astrophysics 352: 495–507, Bibcode:1999A&A...352..495M 
  5. ^ a b c Cenarro, A. J. et al. (2007), "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters", Monthly Notices of the Royal Astronomical Society 374 (2): 664–690, arXiv:astro-ph/0611618, Bibcode:2007MNRAS.374..664C, doi:10.1111/j.1365-2966.2006.11196.x 
  6. ^ Keenan, Philip C.; Barnbaum, Cecilia (June 1999), "Revision and Calibration of MK Luminosity Classes for Cool Giants by HIPPARCOS Parallaxes", The Astrophysical Journal 518 (2): 859–865, Bibcode:1999ApJ...518..859K, doi:10.1086/307311 
  7. ^ Gamma Pyxidis (HIP 43409)
  8. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 17 日